NORWELL, Mass.--(BUSINESS WIRE)--Clean Harbors, Inc. (“Clean Harbors”) (NYSE: CLH) announced today that
it has priced a previously announced private placement of $600 million
of Senior Notes due 2021 (the “Notes”). The size of the private
placement was increased from the previously announced amount of $550
million.

The Notes, which carry an interest rate of 5.125%, were priced at 100.0%
of the aggregate principal amount thereof. The transaction is expected
to close on or about December 7, 2012, subject to customary closing
conditions. Clean Harbors intends to use the net proceeds of the
offering, together with the net proceeds of its follow-on offering of
6.0 million shares of common stock, which was priced on November 27,
2012, to finance a portion of the purchase price for Clean Harbors’
previously announced proposed acquisition of Safety-Kleen, Inc. and its
subsidiaries and related transaction fees and expenses.

The Notes are being offered in the United States to qualified
institutional buyers pursuant to Rule 144A under the Securities Act of
1933, as amended (the “Securities Act”), and outside the United States
pursuant to Regulation S under the Securities Act. This press release
shall not constitute an offer to sell or the solicitation of an offer to
buy, nor shall there be any sale of, the Notes in any jurisdiction in
which such offer, solicitation or sale would be unlawful prior to
registration or qualification under the securities laws of any such
jurisdiction. The Notes will not be registered under the Securities Act
or the securities laws of any other jurisdiction and may not be offered
or sold in the United States absent registration or an applicable
exemption from registration requirements.

Safe Harbor Statement

Any statements contained herein that are not historical facts are
forward-looking statements within the meaning of the Private Securities
Litigation Reform Act of 1995. These forward-looking statements are
generally identifiable by use of the words “believes,” “expects,”
“intends,” “anticipates,” “plans to,” “estimates,” “projects,” or
similar expressions. Such statements may include, but are not limited
to, statements about Clean Harbors’ proposed acquisition of Safety-Kleen
and business outlook and financial guidance and other statements that
are not historical facts. Such statements are based upon the beliefs and
expectations of Clean Harbors’ management as of this date only and are
subject to certain risks and uncertainties that could cause actual
results to differ materially, including, without limitation, those items
identified as “risk factors” in Clean Harbors’ most recently filed Form
10-K and Form 10-Q. Therefore, readers are cautioned not to place undue
reliance on these forward-looking statements. Clean Harbors undertakes
no obligation to revise or publicly release the results of any revision
to these forward-looking statements other than through its various
filings with the Securities and Exchange Commission, which may be viewed
in the “Investors” section of Clean Harbors’ website.

About Clean Harbors

Clean Harbors is the leading provider of environmental, energy and
industrial services throughout North America. The Company serves more
than 60,000 customers, including a majority of the Fortune 500
companies, thousands of smaller private entities and numerous federal,
state, provincial and local governmental agencies.

Headquartered in Norwell, Massachusetts, Clean Harbors has more than 200
locations, including over 50 waste management facilities, throughout
North America in 38 U.S. states, seven Canadian provinces, Mexico and
Puerto Rico.